1. What you're describing here is vBoot. It will download the .Wim files while the device is still in the host OS then boot to it:
2. When the device is re-provisioned, the old inventory instance will be removed/merged with the new (keeping the new name assigned to it). You could use a script, but it wouldn't be necessary due to this feature.
3. Since you're using vBoot, you wouldn't need to call a different template, but you could still. You're able to call templates within templates using action types.
4. The best way to name a PC would be to use the Device Naming Templates. Please see About Device Naming Templates
Very cool Aaron! Thanks for explaining what vBoot did. It wasn't clear to me what exactly it's role was but I figure there must be a way to redeploy in place.
I'm familiar with templates and includes etc but I think it's clear now I don't need to do much with my existing templates except add in the vboot step.